My girlfriend told me that the phrase "You can count on me" exists also in French, with the same meaning and as a literal translation

to count on s.o. => to rely on s.o.

In German, it is also the same

auf jmd. zählen => sich auf jmd. verlassen

I find it rather unusual that the same phrase can be literally translated between three different languages.

(I've found an explanation that says that "zählen" and "rechnen" were used synonymous in the dark ages and probably meant that someone is a constant on which you can rely, he doesn't change his "value" in the calculation.)

So my question is: What it is the origin of the phrase? Is it a common origin in German or English that found its way to the other languages? Or is the origin to be found much earlier, maybe in Latin?

It's the same in Dutch you say: op iemand kunnen rekenen and French, compter sur quelqu'un. I'm from Belgium so I speak Dutch and French. I also wanted to know where it comes from, all I know now it's the same in French, Dutch, German, Englisch and Russian!
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user9018Jul 25 '14 at 19:40

Same in Spanish.....I count on you is Cuento con ustedes. Interesting that so many languages use this saying. Maybe it means I count you as a friend and supporter.
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rooseveltnutNov 15 '14 at 3:27

Idioms are not entirely arbitrary, in fact they are remarkably consistent with various simple, overarching metaphors (read Metaphors we live by if you're interested). Therefore, cross-language idioms are much more common than they would be by pure chance, even when not genetically related.
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Kilian FothJan 24 at 12:56

2 Answers
2

This is not yet a full answer therefore I make it community wiki. I just want to share my ideas. Perhaps it's helpful.

As you know, both German and English are West Germanic languages. French, however, is a Romance language. So, you're presumably wondering why languages with different roots share a meaning. Well, to make it worse I guess Russian, a Slavic language, does have the same idiom, too.

My knowledge of Russian is too little so I can only come up with an example for "mit etw. rechnen". Perhaps someone can help me with an "auf etw. zählen" example. (@RegDwight?)

Another translation for "Auf jemanden zählen" should be "to reckon on sb" while "Auf jemanden verlassen" can be translated to "to rely on sb". Your guess concerning the etymology seems to be a good one, it makes sense to me.